The Seoul Metropolitan Government will take soil and water samples from six spots around U.S. army facilities in the capital to check for any oil contamination.

The city government said the test results will come out early September. It plans to ask the U.S. Forces Korea (USFK) and the Ministry of Environment for a further joint study if any contamination is found.

The city has already called for an extensive survey on possible contamination, but this hasn't happened yet.

A city official said time is running out because many military facilities are moving out of Seoul to Pyeongtaek, Gyeonggi Province, this year.

The six installations include U.S. Army Garrison (USAG) Yongsan's Main Post, Transportation Motor Pool, Seobinggo Compound, Niblo Barracks, Camp Morse and the 8th Army Religious Retreat Center, all in or near Yongsan-gu.

"With relocation so near, we don't even know the extent of contamination. The USFK should cover the cleanup cost. We hope the environment ministry and the USFK will cooperate with us," the city government said in a statement.

Some of the six are currently empty, but the city wasn't given access due to legal issues.

Soil and water contamination have been troublesome for the city government for almost a decade.

It has spent 6.2 billion won in cleaning up two returned military facilities in the city ― Yongsan Garrison's South Post and Camp Kim. However, the levels of toxic chemicals in the soil are still quite high.

The city discovered the contamination near military property in the early 2000s while excavating to build Noksapyeong Station.

In 2015, after other suspected leaks, the Ministry of Environment and the USFK ran a joint study on USAG Yongsan but the results were not made public. The ministry cited the Status of Forces Agreement (SOFA) for its refusal to disclose them. The Supreme Court is currently reviewing the case, after a civic organization sued the ministry demanding disclosure.

The USFK was aware of the severity of the leaks. According to U.S. military files, obtained earlier this year by Green Korea through the U.S. Freedom of Information Act, 84 oil leaks were reported between 1990 and 2015 ― the Korean government had only been notified of five cases.

Seven cases involved 3,780 liters of oil each ― yet only two of these cases were reported to the Korean government.

The issue was also marked by discord between the environment ministry, the city government and civic groups. The ministry claimed rules must be respected in pursuing justice, while the other parties criticized it for failing to represent the interests of citizens.